problem 2 - STM & WMM Flashcards
what is a chunk
a memory unit that consists of several components that are strongly associated with one another
millers magic number 7
7 +/- 2
STM has limited capacity of between 5-9 items
what is the Brown,Peterson & Peterson technique
used to assess how much info STM could hold
involves presenting p’s w some items that they are instructed to remember → P’s then perform a distracting task → after distracting task, p’s are asked to recall the original items
what is the serial position effect?
the U shaped relationship between a words position in a list & its probability of recall
curve shows strong recency & primacy effects
recency vs primacy effect
recency effect = better recall of words at the end of the list - occurs bcuz the final words were still in the STM at the time of recall
primacy effect = enhanced recall for items at the beginning of the list
- presumably remembered for 2 reasons: (1) they don’t need to compete w any earlier items & (2) we rehearse early items more frequently
proactive vs retroactive interference
proactive interference = people have trouble learning new material bcuz previously learned material keeps interfering w their new learning
- primacy effect
retroactive interference = new memories disrupt the retrieval & maintenance of old memories
- recency effect
Wickens et al research (release from proactive interference)
demonstrated that release from PI could also happen when the semantic category of the items was shifted
- employed 5 semantic categories & initially gave p’s 3 trials on the BPP test
- on each trial they saw 3 related words (e.g. given jobs for trials 1,2&3, but then given fruits on trial 4)
- remembered fruits really well & didn’t suffer from PI
- BUT those whose category changed from vegetables to fruits still suffered from PI due to semantic similarity
conclusion: the number of items stored in STM depends on both chunking strategies & word meaning
what is the central executive?
- PL & VSS are slave systems used by the CE for specific purposes = is heavily involved in almost all complex cog activities but does not store info
- prefrontal cortex
- associated w several executive processes
Baddeley’s 4 executive processes
- Focusing attention or concentration
- Dividing attention between 2 stimulus streams
- Switching attention between tasks
- Interfacing w LTM
Miyake et al’s executive functions
identified 3 related (but separable exec functions):
- Inhibition function = used to deliberately override dominant responses & to resist distraction
- Shifting function = used to switch flexibly between tasks or mental sets
- Updating function = used to monitor & engage in rapid addition or deletion of WM contents
Miyake & Friedman (2012) unity/diversity framework
Each exec function consists of what is common to all 3 functions + what is unique to that function
- Common to all: ability to actively maintain task goals & goal-related info + use this info to effectively bias lower-level processing
what is dysexecutive syndrome?
a condition in which damage to the frontal lobes causes impairments to the CE
have problems with:
- Task setting = the ability to set a stimulus response relationship (planning)
- Monitoring = checking the adequacy of one’s task performance
- Energisation = sustained attention or concentration
- Metacognition = recognizing differences between what you know & what you believe
what is the phonological loop?
processes & stores info briefly in a phonological (speech based) form
- Preserves the order in which words are presented
Consists of 2 components:
- A passive phonological store directly concerned w speech perception
- An articulatory process linked w speech production giving access to the phonological store
what is the phonological similarity effect?
the finding that immediate serial recall of verbal material is reduced when the items sounds similar
- doesn’t only involve the PL: semantic processes also play a part
- depends more on acoustic than articulatory similarity
what is the word length effect?
the finding that verbal memory span decreases when longer words are presented
- when p’s engaged in articulatory suppression to prevent rehearsal: eliminated the WLE w visually presented words = the effect depends on rehearsal
what is orthographic neighborhood?
consists of words of the same length differing in only 1 letter
- Short words have more ‘neighbors’ than long words - when short & long words were equated for neighborhood size, the WLE disappeared = WLE may be due more to neighborhood size
what is the visuo-spatial sketchpad?
- Stores & manipulates spatial & visual info
- Visual processing involves remembering what, spatial processing involves remembering where
Consists of 2 components:
1. Visual cache = stores info about visual form & color
2. Inner scribe = processes spatial & movement info
- is involved in the rehearsal of info in the visual cache & transfer info from the visual cache to the CE
evidence for notion of separate visual & spatial systems
Smith & Jonides (1997)
- 2 visual stimuli presented together followed by a probe stimulus
- P’s decided whether the probe was in the same location as one of the initial stimuli or had the same form
- more activity in the right h during spatial task & more activity in the left h during the visual task
Zimmer (2008)
- Areas in the occipital & temporal lobes were activated during visual processing
- Areas in the parietal cortex were activated during spatial processing
Klauer & Zhao (2004)
- spatial interference task disrupted performance more on spatial main task
- visual interference task disrupted performance more on visual main task
what is the episodic buffer?
- Provides temporary storage for integrated info coming from the VSS & PL
- Holds integrated info about episodes or events in a multi-dimensional code combining visual, auditory & other sources of info
- Acts as a buffer between the other components of WM + links WM to perception & LTM
what are the 2 key assumptions concerning the CE, PL & VSS?
all have limited capacity & can function fairly independently of the others.
2 key assumptions:
1. If 2 tasks use the same component, they cannot be performed successfully together
2. If 2 tasks use diff components, it should be possible to perform them as well together as separately
what is articulatory suppression?
rapid repetition of a simple sound which uses the articulatory control process of the PL
- prevent rehearsal
Evaluation of the WM model
+ More active than the Atkins model, not just storage but active processing too
+ Accounts for spatial deficits in brain damaged people’s STM → only selective deficits not overall
+ Less emphasis on verbal rehearsal in the phonological loop than previously
- Oversimplified: smell & taste are not included, spatial is not specific
- Too little research on the interactions among the components
the maxispan procedure
Only rehearsing the first items over & over → articulatory suppression prevents further storage in the phonological loop
- the rest will automatically go into the executive loop
- Prevents transfer between the 2 systems for maximum efficiency
Barouillet et al (maxispan) - method
aim: testing hypothesis that maxispan procedure elicits higher letter spans than the simple span procedure
2 conditions: maxispan & simple span (given no instructions on rehearsing or refreshing techniques & usually overload the phonological loop)
Method:
- Lists of consonants, all letters presented visually but different colors
- Lists were presented in increasing length
- BLUE letters were rehearsed in the PHONOLOGICAL loop
- BLACK letters were only refreshed in the EXECUTIVE loop / episodic buffer
